Description

Biomass and nutrient content of different vegetation components and soil for a transitional moist/dry tropical forest were determined in 1967-68 at Darien Province, Panama. NPP was not estimated.

Situated about 160 km ESE of Panama City, close to the town of Santa Fe, the Darien study site consisted of two plots, about 8 km apart, one of which (Rio Sabana: 8.68 N 78.12 W) was sampled in the dry season and the other (Rio Lara: 8.63 N 78.13 W) in the wet season since the former was inaccesible. Although Rio Lara had a higher numerical density and basal area of trees (45.2 m2/ha) than Rio Sabana (26.4 m2/ha), both plots were considered representative of the surrounding forest. The area was thought to have been forested for the previous 400 years, following abandonment of open savanna lands maintained by the Precolumbian Indians. The region experiences a marked dry season from January to April.

Detailed data are available for biomass and micro-nutrient content (P, K, Ca, Mg, etc.) for stems and leaves of overstorey and understorey, fruit/flowers, dead wood and litter, measured in the dry season (February) and the wet season (September). Apart from litter quantity, most of the differences between these data reflect variation between the two plots sampled, rather than seasonal changes. Total annual leaf and branch fall was 1137 g/m2, giving a minimum estimate of above-ground NPP. Litter decomposition over the 9-month wet season was around 90%.